The fine structure of the frustule of a centric diatomHydrosera triquetraWallich

Abstract
A detailed description of the fine structure of the frustule and processes of silification of Hydrosera triquetra Wallich is presented. The valve is pseudoloculate with simple pore structure on its inner layer. There are two types of girdle-bands. The valvocopula underlaps the valve mantle and overlaps the copula. Each daughter cell retains two parent girdle-bands and forms two new ones during the cell division.